/**
 * @file java.h
 * @brief JAVA
 * @copyright Copyright (C) 1999-2002, 2016 Free Software Foundation, Inc.
 * @copyright Copyright (C) 2024 The C++ Plus Project.
 */
/*
 * This file is part of the cppp-reiconv library.
 *
 * The cppp-reiconv library is free software; you can redistribute it
 * and/or modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either version 3
 * of the License, or (at your option) any later version.
 *
 * The cppp-reiconv library is distributed in the hope that it will be
 * useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with the cppp-reiconv library; see the file LICENSE.
 * If not, see <https://www.gnu.org/licenses/>.
 */

/*
 * This is ISO 8859-1 with \uXXXX escape sequences, denoting Unicode BMP
 * characters. Consecutive pairs of \uXXXX escape sequences in the surrogate
 * range, as in UTF-16, denote Unicode characters outside the BMP.
 */

#ifndef _JAVA_H_
#define _JAVA_H_

#include "reiconv_defines.h"

static int java_mbtowc(conv_t conv, ucs4_t *pwc, const unsigned char *s, size_t n)
{
    unsigned char c;
    ucs4_t wc, wc2;
    int i;

    c = s[0];
    if (c != '\\')
    {
        *pwc = c;
        return 1;
    }
    if (n < 2)
        return RET_TOOFEW(0);
    if (s[1] != 'u')
        goto simply_backslash;
    wc = 0;
    for (i = 2; i < 6; i++)
    {
        if (n <= i)
            return RET_TOOFEW(0);
        c = s[i];
        if (c >= '0' && c <= '9')
            c -= '0';
        else if (c >= 'A' && c <= 'Z')
            c -= 'A' - 10;
        else if (c >= 'a' && c <= 'z')
            c -= 'a' - 10;
        else
            goto simply_backslash;
        wc |= (ucs4_t)c << (4 * (5 - i));
    }
    if (!(wc >= 0xd800 && wc < 0xe000))
    {
        *pwc = wc;
        return 6;
    }
    if (wc >= 0xdc00)
        goto simply_backslash;
    if (n < 7)
        return RET_TOOFEW(0);
    if (s[6] != '\\')
        goto simply_backslash;
    if (n < 8)
        return RET_TOOFEW(0);
    if (s[7] != 'u')
        goto simply_backslash;
    wc2 = 0;
    for (i = 8; i < 12; i++)
    {
        if (n <= i)
            return RET_TOOFEW(0);
        c = s[i];
        if (c >= '0' && c <= '9')
            c -= '0';
        else if (c >= 'A' && c <= 'Z')
            c -= 'A' - 10;
        else if (c >= 'a' && c <= 'z')
            c -= 'a' - 10;
        else
            goto simply_backslash;
        wc2 |= (ucs4_t)c << (4 * (11 - i));
    }
    if (!(wc2 >= 0xdc00 && wc2 < 0xe000))
        goto simply_backslash;
    *pwc = 0x10000 + ((wc - 0xd800) << 10) + (wc2 - 0xdc00);
    return 12;
simply_backslash:
    *pwc = '\\';
    return 1;
}

static int java_wctomb(conv_t conv, unsigned char *r, ucs4_t wc, size_t n)
{
    if (wc < 0x80)
    {
        *r = wc;
        return 1;
    }
    else if (wc < 0x10000)
    {
        if (n >= 6)
        {
            unsigned int i;
            r[0] = '\\';
            r[1] = 'u';
            i = (wc >> 12) & 0x0f;
            r[2] = (i < 10 ? '0' + i : 'a' - 10 + i);
            i = (wc >> 8) & 0x0f;
            r[3] = (i < 10 ? '0' + i : 'a' - 10 + i);
            i = (wc >> 4) & 0x0f;
            r[4] = (i < 10 ? '0' + i : 'a' - 10 + i);
            i = wc & 0x0f;
            r[5] = (i < 10 ? '0' + i : 'a' - 10 + i);
            return 6;
        }
        else
            return RET_TOOSMALL;
    }
    else if (wc < 0x110000)
    {
        if (n >= 12)
        {
            ucs4_t wc1 = 0xd800 + ((wc - 0x10000) >> 10);
            ucs4_t wc2 = 0xdc00 + ((wc - 0x10000) & 0x3ff);
            unsigned int i;
            r[0] = '\\';
            r[1] = 'u';
            i = (wc1 >> 12) & 0x0f;
            r[2] = (i < 10 ? '0' + i : 'a' - 10 + i);
            i = (wc1 >> 8) & 0x0f;
            r[3] = (i < 10 ? '0' + i : 'a' - 10 + i);
            i = (wc1 >> 4) & 0x0f;
            r[4] = (i < 10 ? '0' + i : 'a' - 10 + i);
            i = wc1 & 0x0f;
            r[5] = (i < 10 ? '0' + i : 'a' - 10 + i);
            r[6] = '\\';
            r[7] = 'u';
            i = (wc2 >> 12) & 0x0f;
            r[8] = (i < 10 ? '0' + i : 'a' - 10 + i);
            i = (wc2 >> 8) & 0x0f;
            r[9] = (i < 10 ? '0' + i : 'a' - 10 + i);
            i = (wc2 >> 4) & 0x0f;
            r[10] = (i < 10 ? '0' + i : 'a' - 10 + i);
            i = wc2 & 0x0f;
            r[11] = (i < 10 ? '0' + i : 'a' - 10 + i);
            return 12;
        }
        else
            return RET_TOOSMALL;
    }
    return RET_ILUNI;
}

#endif /* _JAVA_H_ */
